Here's one of many reason why NASA would continue to lie to the public for many decades/generations would be to continuing receiving public FUNDING through TAXES.

As you will learn NASA a an agency created only to serve the government, NASA owe's nothing to the public, but yet they receive our money.

NASA is an agency who creates stories, missions of false explorations to other planets & uses CGI "computer generated images" & then sells to the public as proof they are working exploring, our tax dollars at work. For many generations NASA has been lying to the public and only serving themselves and the powers that be.